Horton

Re: speeding up planning with partitions

Justin Pryzby <pryzby@telsasoft.com>

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From: Justin Pryzby <pryzby@telsasoft.com>
To: David Rowley <david.rowley@2ndquadrant.com>
Cc: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, "Imai, Yoshikazu" <imai.yoshikazu@jp.fujitsu.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-01-07T14:13:32Z
Lists: pgsql-hackers 
On Mon, Jan 07, 2019 at 09:40:50PM +1300, David Rowley wrote:
> On Fri, 4 Jan 2019 at 04:39, Justin Pryzby <pryzby@telsasoft.com> wrote:
> > Running 11dev with your v10 patch applied, this takes 2244ms with empty buffer
> > cache after postmaster restarted on a totally untuned instance (and a new
> > backend, with no cached opened files).
> >
> > I was curious why it took even 2sec, and why it did so many opens() (but not
> > 20k of them that PG11 does):
> 
> It would be pretty hard to know that without seeing the query plan.

The issue was this:
> > It turns out 1050 open()s are due to historic data which is no longer being
> > loaded and therefor never converted to relkind=p (but hasn't exceeded the
> > retention interval so not yet DROPped, either).

So there's no evidence of any issue with the patch.

Justin

Commits

  1. Clean up handling of constraint_exclusion and enable_partition_pruning.

  2. Add test case exercising formerly-unreached code in inheritance_planner.

  3. Speed up planning when partitions can be pruned at plan time.

  4. Avoid crash in partitionwise join planning under GEQO.

  5. Avoid passing query tlist around separately from root->processed_tlist.

  6. Build "other rels" of appendrel baserels in a separate step.

  7. Get rid of duplicate child RTE for a partitioned table.

  8. Rearrange make_partitionedrel_pruneinfo to avoid work when we can't prune.

  9. Don't copy PartitionBoundInfo in set_relation_partition_info.

  10. Move building of child base quals out into a new function

  11. Reorganize planner code moved in b60c39759908

  12. Move inheritance expansion code into its own file

  13. Fix inherited UPDATE/DELETE with UNION ALL subqueries.

  14. Rearrange planner to save the whole PlannerInfo (subroot) for a subquery.